PIL输出图片大于输入

Question

我目前正在开发一个自动脚本，用于使用 PIL (python) 更改文件夹内所有图片的对比度。问题是每张输出图片都比输入一张大...这是我的脚本：

from PIL import Image, ImageEnhance
import piexif

path="C:/User/pictures/"
all_files=["picture1.jpg", "picture2.jpg", "picture3.jpg"]

for i in range(len(all_files)):

    im_path=all_files[i]
    
    
    im = Image.open(path+im_path)
    
    
    #load exif data
    exif_dict = piexif.load(im.info['exif'])
    exif_bytes = piexif.dump(exif_dict)
    
    dpi = im.info["dpi"]
    
    #image brightness enhancer
    contraster = ImageEnhance.Contrast(im)
    
    im_output = contraster.enhance(factor)
    im_output.save(new_path+im_path, format="JPEG", quality=100, dpi=dpi, exif=exif_bytes, subsampling=0)

比如我传入的jpg图片是8.08Mo，新的是15.8Mo，即使我选择了0%的对比度变化...

感谢a的回答，周末愉快

Answer 1

您已针对图书馆作者的 recommendations 指定 quality=100。

The image quality, on a scale from 0 (worst) to 95 (best). The default is 75. Values above 95 should be avoided; 100 disables portions of the JPEG compression algorithm, and results in large files with hardly any gain in image quality.

PIL输出图片大于输入

PIL output picture bigger than input

image

filesize

python-imaging-library